3.6L Cam Bearing Questions

[Porshaah]

Hi All

Am I correct in assuming that if the bearing in the cam towers are worn (i.e. they are more likely to wear as the material is softer than the cam shaft) or the cam journal, that in order to renew one will likely need to perform a line bore on the cam towers first, followed by adding material to the cam shaft journal by either method of welding or chroming, and in turn machining/polishing to the new larger diameter cam bearing? What is the desired clearance on the cam journal to cam bearing? What is the maximum wear clearance between the cam bearing and the cam journal before machine work is required?

All responses welcome
Bill

[mamut]

If the cam housings are scored, lots of wear, you are better off replacing them, btdt, cheers.

[Henry Schmidt]

If the cam towers aren't scored, there is more than a good chance that they are still useable.
If they are scored, chuck them in the trash and find a good set of used ones.

[Porshaah]

Thank you Mamut & Henry

I'm not seeing any scoring I'm concerned with normal wear and what the acceptable clearances should be between the bearing and the cam journal before any machine work is required.

Again all response welcome
Bill

[jcge]

From 993 tech spec book

Bearing diameter= 48.967mm to 48.992mm
Cam diameter = 48.926mm to 48.942mm
Clearance = 0.025mm to 0.066mm
Wear limit 0.1mm (absolute max clearance)

[Porshaah]

Thanks jcge